The present invention broadly relates to rotary cutters of the type suitable for use for milling, planing, size reduction, pelletizing, and the like, and more particularly, is directed to an improved rotary cutter having wear resistant tipped cutting teeth disposed on a true geometrical helix. A variety of rotary cutters have heretofore been used or proposed for use for various cutting and milling operations which are comprised of high strength wear resistant tool steels and special alloys in an effort to prolong the useful cutting life of the toothed elements thereon between sharpening operations. The disposition of the cutting edges on a true geometrical helix provides for distinct advantages in the efficiency of operation of the rotary cutter as well as in the cutting action obtained. In the use of such helical rotary cutters for pelletizing or comminuting filaments and strands of various plastic materials the abrasive nature of many such plastics has occasioned a relatively rapid degree of wear of the cutting edges in spite of the use of special tool steels and alloys. The loss of sharpness of the cutting edges during such pelletizing operations is accompanied by a reduction in efficiency and an increased quantity of unusable fines produced as well as irregularity in the size and/or shape of the pellets produced.
There has, accordingly, been a long felt heretofore unfilled need for rotary helical cutters incorporating cutting edges comprised of a hard wear resistant material such as a sintered or cemented carbide material which substantially prolongs the useful operating life of the cutter thereby substantially reducing the costly and time consuming practice of frequent resharpening operations and the associated down time of the process and loss of production.
The present invention overcomes the problems and disadvantages associated with rotary cutters of the types heretofore known providing for a rotary helical cutter and method of fabricating such cutter in which at least the cutting edge portions are comprised of a hard wear resistant material and are oriented in a true geometrical helical configuration providing for optimum efficiency and cutting action. The present invention further provides a rotary cutter which is of simple manufacture, durable operation, which incorporates a plurality of identical cutting discs enabling simple replacement of individual damaged cutting discs and which substantially reduces the frequency of sharpening cycles and loss of valuable productivity.